The present invention relates to a latch for overhang optical assemblies. The assemblies include a mounting member with a frame pivotally attached thereto. The latch that locks and unlocks the frame with respect to the mounting member. The latch facilitates easy access to the optical unit supported by the mounting member and optical lens supported by the frame.
An overhang optical assembly, such as a canopy luminaire, is commonly mounted and overhung from a pole or ceiling either outdoors or indoors. The prior art optical assemblies combine a luminaire lens and lens frame with a latch for locking the lens frame to an optical assembly mounting frame. The mounting frame is attached to a luminaire housing or to another support. The lens and lens frame are movable between open and closed positions. In the open position, the lamp can be changed and the optical features (e.g. the reflector) inside the lens can be adjusted.
Gaining access to the optical unit within the prior art optical assemblies is typically difficult because a special tool, such as a probe or hook, is required to unlock the latch. In addition, access to the optical unit normally requires that the entire assembly be uninstalled. These difficulties are particularly acute when the luminaire, as is usually the case, is located a significant distance above ground level.
Other problems with present day optical assemblies are that the latches do not provide a weather tight closure thus allowing the elements of the surrounding environment, such as rain and dirt, to enter the interior of the assembly. Also, the prior art latches do not provide a means for ensuring that the lens frame of the optical assembly is positively locked to the mounting member. The lens frame may only be partially locked rather than completely locked. In addition, the latches of the conventional optical assemblies are bulky and protrude from the exposed lens frame, and thus, are not aesthetically pleasing. Finally, the conventional latches for optically assemblies are typically complicated and costly to manufacture.
Accordingly, an object of the present invention is to provide an optical assembly that includes a mounting member, a movable frame, and a toolless entry latch allowing easy access to the optical unit within the assembly.
Another object of the present invention is to provide an optical assembly that includes a latch that provides a weather tight closure between the mounting member and the frame.
A further object of the present invention is to provide an optical assembly that includes a latch with a positive locking feature.
Yet another object of the present invention is to provide an optical assembly including a compact and simply operable latch that is simple and cost efficient to manufacture and is aesthetically pleasing and rugged.
The foregoing objects are basically attained by an optical assembly comprising a frame member for holding an optical member having a positioning surface and a mounting member releasably coupled to the frame member, the mounting member having an engaging surface. The two members are relatively movable between open and closed positions. A latch member is coupled to the frame member and pivotally movable between locked and unlocked positions relative to the frame and mounting members. The latch member includes a main body portion with first and second surfaces, a cam arm portion extending from the first surface at a first end of the main body portion and engaging the engaging surface of the mounting member when the latch member is in its locked position, and a handle portion extending from the first surface at an opposing second end of the main body portion.
By forming the optical assembly in this manner, the latch can be unlocked without a tool by pushing and gripping the handle portion to facilitate access to the optical assembly interior. This latch also provides a positive, weather tight seal, and is simple to use, is inexpensive to manufacture, presents an aesthetic appearance.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which taken in conjunction with the annexed drawings, discloses a preferred embodiment of the invention.